The present invention relates to a substrate processing system in which substrates such as semiconductor wafers are successively transferred into various processing device by plural arm mechanisms and, then, applying process liquid to the substrate and, heat treating the substrate.
A substrate processing system, in which semiconductor wafers are successively coated with a resist solution and, then, the coated resist is developed, is used in a photolithography process. A substrate processing system of this type is disclosed in, for example, U.S. patent applications Ser. Nos. 08/667,712 and 08/686,707.
FIG. 1 shows a conventional substrate processing system 101. As shown in the drawing, the system 101 comprises various processing devices 111 to 117, arm mechanisms 103, 104, 106, and a load/unload section 102. A semiconductor wafer W is taken out by the sub-arm mechanism 103 from a cassette C arranged in the load/unload section 102, delivered from the sub-arm mechanism 103 onto the first main arm mechanism 104 and, then, transferred successively by the first and second main arm mechanisms 104, 106 into the processing devices 111 to 117. After various processing in these devices 111 to 117, the wafer W is brought back into the cassette C.
The conventional substrate processing system 101 occupies a large floor area, making it necessary to use a large clean room housing the system 101. Naturally, the burden given to the air conditioning facilities is increased for supplying a down-flow air stream within the clean room.
Also, in the conventional processing system 101, a transfer path 105 within the load/unload section 102 extends to intersect at right angles with a transfer path 107 within a process section 110 within an XY plane. To be more specific, the transfer path 105 for the sub-arm mechanism 103 extends in an X-axis direction, with the transfer path 107 for the main arm mechanism 104 extending in a Y-axis direction. In other words, these transfer paths 105 and 107 are arranged to form a T-shaped passageway. It follows that it is absolutely necessary for each of the sub-arm mechanism 103 and the main arm mechanism 104 to transfer the wafer W through a crossing 109 of the T-shaped passageway, with the result that an unduly long time is required for the delivery of the wafer W between the arm mechanisms 103 and 104.